sim Package

Gazebo Harmonic simulation backend — world generation, multi-vehicle spawning, hoop-course scoring, and stage configuration.

Extra Dependency

sudo apt install ros-humble-tf-transformations
python3 -m pip install "pydantic>=2,<3"

Current SAE Sim Launch Behavior

The SAE sim stack is launched through:

ros2 launch uav main.launch.py

Simulation now defaults to launching Gazebo with the GUI enabled.

To force headless mode, set either:

export SAE_SIM_GUI=0

or

export SAE_SIM_HEADLESS=1

before running the launch command.

Notes: - Gazebo is launched directly with gz sim. - The render engine is forced to ogre. - A workspace-owned Gazebo server.config is used. - GUI startup scrubs OpenCV Qt plugin env vars before launching Gazebo.

Multi-Vehicle Backend Contract

src/sim/launch/sim.launch.py now accepts an optional backend_json:=... launch argument. The JSON object selects a canonical stage YAML by world_name plus optional mission_stage, then applies any world_overrides on top of it.

Recommended shape:

{
  "world_name": "sae",
  "mission_stage": "payload_retreat"
}

Notes: - omitting mission_stage resolves base.yaml - the canonical stage YAML should define spawnable props under world.params.entities and vehicles under world.params.controllables - UAV controllables should carry an explicit px4_airframe_id; for valid values, inspect PX4-Autopilot/ROMFS/px4fmu_common/init.d-posix/airframes - world_overrides should follow the same entities / controllables split and is still available for incidental stage tweaks, but it should not be used to supply PX4 airframe identity - legacy embedded backend.world input is intentionally no longer supported - legacy top-level spawnable records are no longer supported; use world.params.entities - legacy single-UAV spawning remains available for older launch paths that still pass spawn_uav_model:=true - scoring nodes use explicit scoring.params.vehicle_name to bind PX4 state under /<vehicle_name>/fmu/... - if a scoring stage has multiple UAV controllables and no explicit vehicle_name, launch fails instead of guessing